The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 04, 2018
Filed:
Aug. 01, 2016
Fujitsu Limited, Kawasaki-shi, Kanagawa, JP;
Goji Nakagawa, Sagamihara, JP;
FUJITSU LIMITED, Kawasaki, JP;
Abstract
An optical receiver receives signal light obtained by superimposing a second signal to a first signal according to a predetermined superimposition pattern. In the optical receiver, a tunable optical filter allows a part of a spectrum of the received light to pass, and a photodetector converts the transmission light into an electrical signal. A filter controller controls a center transmittance frequency of the tunable optical filter in response to a superimposed period and a non-superimposed period of the second signal identified based on the electrical signal. A superimposed signal detector detects the second signal based on the electrical signal obtained in response to the control of the tunable optical filter during the superimposed period. An optical signal-to-noise ratio (OSNR) calculator calculates an OSNR of the signal light based on the electrical signal obtained in response to the control of the tunable optical filter during the non-superimposed period.